Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined 50 untreated parkinsonian patients with a complaint of tremor for the presence of a resting, postural, or kinetic tremor. Tremors were recorded by an accelerometer to determine amplitude and frequency. A postural tremor was present in 92% and a resting tremor in 76%. The amplitude of postural tremor was greater than resting tremor in 50%, the same in 25%, and less in 25%. The average tremor frequency of resting and postural tremor was not significantly different. Carbidopa/levodopa reduced testing tremor in 58% and postural tremor in 46% of patients. The dopamine agonist naxoglide (PHNO) reduced resting tremor in 77% and postural tremor in 70% of patients. Postural tremor was not worsened by either drug. It is concluded that tremors in both the resting and postural positions are an integral part of the symptoms of Parkinson's disease and that both tremors have a similar frequency and pharmacological responsiveness in the early phases of the disease.
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PMID:Tremors in early Parkinson's disease. 280 93

This study was designed to compare the initial tremor response to 4.0 mg albuterol and 5.0 mg terbutaline orally administered and to study the question of tachyphylaxis by rechallenge after 3 wk of maintenance dosing. Twenty fasting patients with severe COPD in whom orally administered sympathomimetics were withheld for 2 wk were challenged with single doses of each drug in a crossover, randomized fashion 1 wk apart. Then after a further 3 wk of dosing 3 times a day of the second medication (10 patients received each medication), they were challenged once more 16 h after the last dose. Rest and postural tremor were measured at zero and 2 h using an accelerometer affixed to the finger, and measurements of subjective tremor, tremor power spectrum, plasma cyclic AMP and lactate, and forced vital capacity were also made. Postural tremor increased from 25.05 to 36.20 relative units for albuterol, an increase of 11.15 units, and from 24.90 to 57.70 units for terbutaline, an increase of 32.80 units (difference significant at p = 0.01). Plasma cyclic AMP (p less than 0.01) and lactate (p = 0.05) increases were also less for albuterol, and the FEV1 and FVC responses, though about one third less, did not differ significantly. After 3 wk, mean baseline tremor for both drugs was elevated even 16 h after the last 3 times a day dosing (38.00 and 33.10) for albuterol and terbutaline (difference, NS), and responses were much less to the single tablet (3.40 and 9.10, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparison of tremor responses to orally administered albuterol and terbutaline. 376 27

The pathophysiology of postural tremor was studied in 7 patients with cortical cerebellar atrophy, and compared with the responses of 14 healthy control subjects to the same tests. Both tibial nerves were simultaneously and selectively stimulated in the fossa poplitea. EMG was recorded from agonist gastrocnemius muscles and from the antagonistic anterior tibial muscles. Displacement of the centre of foot pressure, inclination of trunk and head in the anteroposterior direction, and the ankle angle were also measured. Patients and controls both exhibit a synchronized discharge in the anterior tibial muscle (antagonist) with a latency of 120 ms to stimulus onset (tib1). Tib1 is shown to be a segmental stretch reflex elicited by the contraction of the gastrocnemius (agonist). A later, presumed long-loop response occurs after another 120 ms both in gastrocnemii and anterior tibial muscles in the normal subjects. This latency, and the amplitude of the late reflex, are increased in the patient group. The synchronization of delayed long-loop reflexes and a stretch response of the gastrocnemius in response to tib1 terminate the first cycle of the postural tremor which thereafter continues by way of the same mechanism generating a contraction of the anterior tibial muscle. Postural tremor can thus be synchronized by a single bilateral electrical stimulus and can even be elicited in incipient cases of the disease. With further progression of the cerebellar atrophy the dominant frequency of the postural tremor decreases along with an increase of long-loop latencies.
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PMID:Delayed and enhanced long latency reflexes as the possible cause of postural tremor in late cerebellar atrophy. 747 Aug 47

Postural tremor was recorded from psychiatric patients who had been treated with phenothiazine or butyrophenone neuroleptic drugs. None of the patients had previously been diagnosed as having extrapyramidal dysfunction. A significant number of these patients had abnormally low tremor frequencies. Low frequency tremors are often associated with Parkinson's disease (PD) so that some of these patients may have early signs of drug induced Parkinsonism (DIP). The results indicate that DIP is not necessarily characterised by a bilateral slow frequency tremor, but may initially be similar to idiopathic PD, even though its cause and prognosis are different.
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PMID:A study of the early signs of drug induced parkinsonism. 809 40

The basal ganglia play important roles in the pathophysiology of various types of involuntary movement disorders, such as chorea, ballism, athetosis, dystonia, tremor and tics. These involuntary movements when occur in the childhood show the specific ages of onset and the courses. For example postural dystonia occurs in childhood but action dystonia tend to occur in later ages. Postural tremor occurs after the second decades but resting tremor does not occur in childhood. Furthermore drug induced dystonia but not levodopa induced dyskinesia occurs in childhood. The age dependent clinical features observed in these involuntary movements are thought to be due to the specific developmental processes of the pathway in the basal ganglia and its efferent projections, which are involved in the pathophysiology in the each disorder. For example, the dopamine activity is known to be increased in the striatum before ten years of age which decreases, rapidly during the first decade and further decreases in the next decade with the moderate degree till adult level. The direct pathway, which is predominant in the ventral area in the basal ganglia, matures earlier than the indirect pathway, which is predominant in the dorsal area. In this paper the pathophysiologies of the hereditary progressive dystonia with marked diurnal fluctuation, juvenile parkinsonism, idiopathic torsion dystonia, chorea, ballismus and tics, all of which occur in the childhood, are discussed from the view point of the age dependent specificities of the involved pathways in the basal ganglia and their projections during development.
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PMID:[The clinical characteristics of involuntary movements in childhood]. 914 24

Segawa disease (hereditary progressive dystonia with marked diurnal fluctuation) is an autosomal dominant, childhood onset, postural dystonia and the first hereditary basal ganglia disorder whose causative enzyme and gene defect were clarified. The initial symptom is unilateral pes equinovarus with marked diurnal fluctuation. Progression becomes slower after mid-teens and stationary after thirties. Postural tremor may occur after 10 years of age, especially after thirties. Parkinsonian resting tremor action and torsion dystonia. and disturbed locomotion do not occur. L-Dopa shows marked and sustained effect without side effects. F-Dopa PET and [11C] raclopride PET of over 20-year-old cases are normal. Deficiency of GTP cyclohydrolase I (GCH-I) was suggested from low CSF biopterin and neopterin. Mutation of GCH-I gene and decreased GCH-I were clarified as etiology. Twenty-five mutations discordant among families have been found. Autopsy of a gene proven case revealed decreased striatal tyrosine hydroxylase (TH) and dopamine (DA) in ventral striatum where direct pathway is predominant. Decreased GCH-I causes decreased tetrahydrobiopterin (BH4), TH and DA in nigrostriatal (NS) terminal. The lowest affinity of BH4 to TH causes selective involvement of DA. Postural dystonia is caused by decreased TH and DA affecting D1-direct pathway. Thalamic ventrolateral and pedunculo-pontine nuclei are spared. Diurnal fluctuation of symptoms is due to diurnal fluctuation of TH and DA at NS-DA terminal. Decreased DA to below 20% of normal, shown by polysomnographical studies, and its physiological age related decremental changes in NS-DA terminal underlies characteristic clinical course. High D2 receptor before early thirties masks D1 related hypertonus and manifest progression before 20 years of age. Other pteridine abnormalities also cause dopa responsive postural dystonia with diurnal fluctuation. A case of juvenile parkinsonism without dystonia showed decreased TH in dorsolateral putamen where indirect pathway is predominant. These suggest that decreased TH due to decreased BH4 involves D1-direct pathway causing dystonia, and decreased TH itself involves D2-indirect pathway causing parkinsonism.
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PMID:[Segawa disease]. 957 70

The authors report three Japanese families presenting with cortical tremor and epilepsy. The patients showed either tremulous finger movements or seizures as the initial symptoms between 19 and 30 years of the age without progression. Postural tremor resembled essential tremor and responded to the anticonvulsants such as clonazepam, primidone and sodium valproate. Seizures were infrequent. These patients seem to have the same disorder as what the authors have described as 'familial cortical tremor with epilepsy'. Familial cortical tremor must be more common than previously thought and should be taken into consideration in the patients with 'familial essential tremor' who do not respond well to beta-blockers.
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PMID:Familial cortical tremor with epilepsy: an under-recognized familial tremor. 963 12

Clinical tremor analysis mostly is used for the measurement of tremor frequency. The analysis is based on short segments of EMG recordings and on clinical ratings of tremor intensity. Accelerometry appears to have some practical advantages. The present study was concerned with the development of a methodology for assessing tremor activity using the three parameters, frequency (Hz), amplitude (g), and occurrence of tremor (in per cent of time). These parameters were derived from joint amplitude frequency analysis of the calibrated accelerometer raw signal and from appropriate decision rules. This methodology was used in connection with 27 patients with Parkinson's disease, to investigate the aforesaid parameters of tremor activity. Postural tremor had a higher occurrence time (right-hand only) and higher frequency (left-hand only) than resting tremor, however, the average amplitudes did not differ. The correlations between right-hand and left-hand measures were higher during postural tremor test. Frequency was not correlated to amplitude or occurrence time, however, moderate correlations did exist between amplitude and occurrence time. In addition to the assessment of tremor activity, multi-channel accelerometry may be used for the detection of posture and motion. Further applications of this methodology, for example, in 24 hr ambulatory monitoring of tremor, are discussed.
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PMID:Joint amplitude and frequency analysis of tremor activity. 1007 56

The effect of low level exposure to manganese (Mn) was examined in 297 subjects from southwest Quebec. Blood manganese (MnB) levels as well as other possibly relevant variables were obtained. We tested equipment and analysis procedures that we have developed to quantify aspects of motor function thought to be affected by exposure to toxins, in particular, rapid alternating movements, rapid and precise pointing movements, and tremor. (1) The eurythmokinesimeter measures timing and precision of contacts between a hand-held stylus and a pair of metal targets (proximal/distal). This roughly approximates the finger-to-nose test of the UPDRS. Characteristics quantifying speed, precision and regularity of the movements were calculated, as well as multiple contacts due to tremor and an index based on Fitts' Law eliminating the effect of the trade-off between speed and precision. (2) The diadochokinesimeter accurately measures rapid rotation of the forearms (pronation/supination). Characteristics quantifying the range, speed, period, shape and regularity of the oscillatory movements were calculated, as well as the smoothness of the movement on a fine scale and the coordination between the two hands. (3) Postural tremor of the arm and hand was measured using the accelerometry-based "TREMOR" system of Danish Product Development. We used the amplitude and frequency characteristics provided by the TREMOR system: intensity, center frequency, dispersion and harmonic index. Previous studies have shown that these tests are sufficiently sensitive to detect small differences in performance of different groups of subjects, with indications that some characteristics are also specific to particular conditions. In this study, significant though small effects related to age and gender were found in many of the characteristics. When effects of other variables are removed, low-level exposure to Mn was found to be associated with a decrease in ability to perform regular, rapid and precise pointing movements, a decrease in ability to attain high maximum rotation speeds in rapid alternating movements, and an increase in regularity of tremor oscillations. Moreover, the effects are age-related for levels of MnB 7.5, micrograms/L.
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PMID:Quantification of neuromotor function for detection of the effects of manganese. 1038 96

The manner in which characteristics of time series in the frequency domain can enhance discrimination between physiologic and parkinsonian tremor when tremor amplitude is low was examined. Rest tremor and postural tremor with and without visual feedback were recorded twice in the two hands of a group of patients with Parkinson's disease (PD) (n = 21) and a group of healthy control subjects (n = 30) using displacement laser systems. Recordings were analyzed quantitatively using amplitude and seven frequency domain characteristics. Postural tremor with no visual feedback allowed the most efficient discrimination between the two groups of subjects especially in velocity and acceleration (derived from displacement) and allowed identification of more patients with PD as separate from the range observed in the control group. Moreover, the frequency domain characteristics that were investigated identified the majority of the patients even when amplitude did not. After eliminating redundant (correlated) characteristics, it was found that the frequency composition of tremor in PD can be described adequately with four characteristics, which are the most reliable, independent, and discriminative elements for detecting early or subtle modifications in tremor. Also, a series of finger flexions was found to enhance physiologic tremor but not tremor in PD. Discrimination of low-amplitude tremor in PD from normal physiologic tremor is enhanced by examining the median frequency of oscillations, the concentration of power in the power spectrum, and the distribution of power in particular ranges. Tremor measurement should not be limited to acceleration data as some information is more visible in velocity time series.
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PMID:Using frequency domain characteristics to discriminate physiologic and parkinsonian tremors. 1057 31


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